Tuesday, June 19, 2012

While we were waiting for it to get dark on Friday night, my brother and sister helped me make some light paintings on my iPhone using nothing but Slow Shutter Cam (). Dang, I feel like I should be on Slow Shutter Cam payroll by now since I've mentioned it in no less than 6 different blog posts!

In my previous post, I noticed something in my star circle photo that wasn't a plane like the rest of the non-star objects. Based on the appearance of the streak, I concluded that it was an Iridium flare cut in half by my camera's processing time between two consecutive 15 second exposures.

Iridium 80 above Indiana on June 15, 2012 at 11:30pm

How could I prove that it was an Iridium flare? How would I know which individual satellite is in my image? I tried looking up the object on Heavens Above, but the Iridium flare data only went back to the past 48 hours. I noticed that the Heavens Above URL basically includes the information used to calculate the numbers in the table, so I started to mess around with the values.

Here is the URL for the "previous 48 hrs" Iridium flare list (on the day I wrote this):http://www.heavens-above.com/iridium.asp?Dur=2&Date=41077.7391100926&lat=39.95502&lng=-86.00647&loc=Fishers%2c+IN&alt=0&tz=EST

Notice that the URL itself includes the information displayed in the table. We have the coordinates, the time zone, and values of Dur=2 and Date=41077. Dur=2 stands for duration of 2, or two days displayed on the table. The date threw me off at first, because we are definitely not in the year 41077 yet! I changed the date to Date=1 and the table jumped to January 1, 1900.

So the date=## in the URL is the number of days since January 1, 1900. I was able to find my Iridium flare from last weekend by turning the date back by a couple of days: From 41077 to 41075.

Now my Iridium flare from Friday night shows up in the table! Sure enough, a flare of magnitude -4 at 30° elevation in the NE sky fits the image I captured perfectly! It looks like Iridium 80 was the culprit.

These two images were my longest star trail stacks to date, the first with 107 and the second with 109 stacked images (15 sec exposure each). My plan was to tape the shutter down and let the battery die, but I came out to find my first exposure had stopped because the tape lost its grip after an hour and a half or so.

My second image began at around 2:00am and went until the battery died. I taped the shutter down while the camera was on a table instead of pressing down on the camera while mounted on the tripod, this let me press down with more force to secure the shutter with my mechanical pencil eraser.

Possible Iridium flare cut off by my camera between exposures

Here is a close-up of an object in the first photo that does not appear to be a plane like the rest of the lights. My guess would be that this is a satellite coming into view that is cut off by the 15 sec exposure. This seems to fit the description of an Iridium flare coming into view and fading out again without traveling very far across the sky. The Iridium flare on Wikipedia shows a 30 second exposure that matches the beginning and end of my flare, which was cut in half by the camera's processing time.

I don't usually let to take photos until the battery dies, because I'm nervous about leaving my camera out in front of my apartment complex. That's why it was such a treat to visit my brother at his house in Fishers, because I could let my camera go and go!

Here's a picture of my brother learning how to do star trail photography with his Nikon D3000. His trails didn't turn out as good as mine, but he's just beginning!

Brian getting into astrophotography for the first time

He was so excited, we even got up on the roof to check out the view - deciding later that the roof was too steep for a tripod observatory.

Rooftop view of Fishers, IN taken with iPhone at 9:53pm

Finally, here is a video showing the creation of the star trails. I saved each composite image in StarStaX so the trails appear to grow over time.

Monday, June 18, 2012

I'm not sure if it's because the lightning was so bright, or because I was shooting through the side window of my car, but the lightning is creating some pretty epic lens flares in this photo!

I was using Slow Shutter Cam app for iPhone in Light Trail mode with a light sensitivity of 1.

I was driving home from Indiana on Saturday when I saw some huge lightning bolts streaking through the sky in front of my car. It wasn't raining yet, so I thought it would be a good time to try photographing lightning with my iPhone for the first time.

I pulled off the highway and stopped in a church parking lot. I pressed my camera up against the drive side window and started taking light trail pictures with the app.

Not as impressive as other photos of lightning I've seen with an iPhone, but not bad for shooting through a window during daylight. I also think the lens flares add something cool to the photos even though it's basically just a glare caused by the window of my car.

I had just turned 13 when The Great Comet of 1997 appeared in the light-polluted skies over the suburbs of Dayton, Ohio. I don't remember hearing much about it, an occasional photo in the paper kept me interested for a few minutes possibly. Looking through Wikipedia now, I'm astonished that the thing was visible for several months!

My 7th grade handwriting, looks about the same now

On the afternoon of March 23, 1997 my parents took me to our neighborhood Motophoto (do these still exist?) to get a special kind of film for low-light photography. I looked through my camera's manual to learn that I had a way to do long-exposure shots by holding down the shutter button.
That night, I went into the field across the street with my dad to set up the tripod and take some photos of the comet that was faintly visible to the west. Holding the shutter button down by hand, I snapped some long exposure photos (about 15 seconds each).

Hale-Bopp higher in the sky on the evening of March 23, 1997

I didn't realize it at the time, but according to Wikipedia, "Hale–Bopp had its closest approach to Earth on March 22, 1997 at a distance of 1.315 AU." This is probably why there was an article in the Dayton Daily News which prompted my parents to suggest a photography expedition that next evening.

I remember taking my photos in to 7th grade science class at Watt's Middle School. The teacher and the other students were very impressed, and remarked at my cleverness as they passed the photos around the room (or at least that's how I remember it).

This comet had a large impact on my interest in science and the night sky, and I eagerly await its return in the year 4385!

Thursday, June 14, 2012

I grabbed this screenshot of Asteroid LZ1 from the SLOOH SpaceCamera live streaming event going on right now. They are saying the asteroid has the apparent brightness of the dwarf planet Pluto in the sky, and was only discovered a few days ago. The asteroid is the little white dot traveling 10 miles per second, and the lines are star trails.

Cool stuff! I learned about the asteroid from @TravelinMike and the post on Mashable but I figured I would need a membership to see the asteroid. I was pleasantly surprised the show was free, and I'll certainly check back with SLOOH for more of their events.

Saturday, June 9, 2012

Not sure if these are altocumulus or cirrocumulus clouds, but they're mixed in with jet streams. I didn't realize jet trails moved intact horizontally, I figured they would dissipate before being carried by the wind as a whole unit. See, I learned something!

I decided to turn several of the sequence shots I used to make my stacked star trail photos into a Vimeo movie showing the motion through the sky. It's a little choppy, and it looks better when I crank the speed up a bit - however, if I ran it any faster the video would become too short - so it's a little slow.

So this is my second attempt at recording a time lapse sunrise on my iPhone, and it's the second time the light totally white washed the entire video. The results are similar to my first attempt. At least I used the auto-start timer so I didn't lose any sleep over it!

Friday, June 8, 2012

Ok, so I'm writing this post as a public question to anyone who knows more about lenses and transits than I do (which isn't much to begin with). I've seen a couple photos pop up on Instagram where the IGers (Instagrammers) claim to have captured the Transit of Venus in their lens flare.

Can anyone say with authority if this is actually Venus showing up in the lens flare? I know eclipses do weird things to light passing through tree leaves, and pinhole cameras can project the transit onto paper, so it seems plausible that something funny is going on with the lens to make Venus visible.

However, upon further Instagram lens flare research using the recent Annular Eclipse as a reference, it appears the inner white dot of the lens flare corresponds to the image of the entire Sun and not a dot on the sun.

Here are some examples of the eclipse visible in the lens flare (I added the arrows):

So my conclusion is that the Transit of Venus was NOT visible as a lens flare because the white dot at the center of the flare corresponds to the entire solar disc and not a shadow on the disc. On the other hand, it appears that the lens flare is a convincing way to capture images of an eclipse using nothing but an iPhone camera - pretty cool!

Since my last attempt at photographing the ISS on an iPhone turned out rather boring, I tried to get a little more foreground into my shot this time. I actually took this photo from inside my bedroom looking out over the parking lot of my apartment complex. The flyover was early in the night (9:54pm) so the sky was even lighter than it appears in the photo.

Currently, there are around 8,000 photos on Instagram with the tag #astronomy. Using a simple widget, I've embedded the latest results here in my blog. The widget is called SnapWidget, and it's the best way to embed Instagram photos on Blogger (or other sites).

A lot of the photos are re-posts of professional photographs or NASA images, others are iPhone photos of the moon that look like a little white dot in the sky, but every now and then some pretty amazing original photos come through the feed!

I am not bothered by the iPhone photos of the moon as a little white dot because at least people are interested in the night sky enough to snap a photo or two. I think it's a good sign that people are still interested in what's going on up there.

Wednesday, June 6, 2012

No slapdash iPhone astrophotography blog would be complete without a barley discernable image of the International Space Station streaking across the sky, as captured by the Slow Shutter Cam app.

I used Light Trail mode with exposure length on B for "bulb" and light sensitivity at 1.

A car pulled into the parking lot right as the ISS was diving into Ursa Major, so I cut the exposure short. I'm glad I did, because otherwise I would have just had a white line on a blue background. At least now it sort of looks like something streaking through the sky.

Hey, it's not pretty, but it's an authentic photo of the ISS from Earth using nothing but an iPhone!

Next time I'll try to get some foreground in the shot. There is an early sighting of the ISS over northwest Ohio on Saturday, June 9 around 9:41pm. The sky might still be light enough to see some color and foreground objects.

Venus is clearly visible (through this somewhat dusty eyepiece) as a small black dot about 1/30th the diameter of the Sun.

I'm not sure why the position of Venus is so whack-a-doo in each of the photos, I'm guessing it has something to do with the mirrors reversing and flipping the image, and then my iPhone turning sideways to get a good angle for the picture.

I'm so glad I was able to observe this rare event! I feel privileged to have casually snapped some pictures on my iPhone, while astronomers observing previous transits had to trace the silhouette by hand.

Views This Month

Advertising

Feel free to contact me with inquiries for advertising, guest posts, or other promotions. While I don't do a lot of these, I'm not opposed to it - especially if the content is relevant to this blog. Thanks!